I drove my 74 bus to Lake Wales, FL (near Orlando) last week. Came back the next night. The outside air temp got into the mid 90s, and the cabin temp was over 100º until well after the sun set. I stayed off the highways and limited my speed based on cylinder head temperature. I kept it below 410º, which is where I've set the CHT gauge to start blinking. That meant speeds from the high 40s to mid 50s. In the Camry the trip takes 7.5 hrs, this trip took 11.5. I don't mind the extra time and the non-highway route is much more pleasant than I-75, but I want to be sure I'm not burning up my engine. Outside air temp didn't seem to have an impact on engine temp, it seemed to be all about the speed. The bus is tuned properly and it ran (walked?) well. I know 410 isn't ideal but is it satisfactory? Any thoughts or suggestions? JM

hmm, if the bus wouldn't do 55-60 without hitting 410+ then something isn't right. Others would know more but I wonder if you need to go up a main jet size...maybe too lean? Is there some place you could put it on an exhaust gas anyalyzer (if you find one, let me know, lol) I'm still fighting high CHTs as well. Mine usually happen on hills and at speeds above 60.

***don't take anything said here as truth, I'm still trying to figure it all out as well***_________________1969 Beetle
1974 Westy FI Conversion

I took Greg's advice and increased the jet size just a bit. I drove to Nashville this week and ran mostly between 360 and 390 degrees, doing mid to hi 50s and occasionally over 60 mph. While the outside temp was cooler than for my FL trip, this was a much harder trip on the bus (mountains.) I still hit 410 degrees and had to back off many times, mostly uphill, but not nearly as often as I did going to FL.

Apparently busses are rare up there because people came spilling out of shops and gas stations to tour the bus and tell me their VW stories. And the women! On this trip the bus was quite the babe magnet. Well, to be accurate, a babes-in-their-70s magnet. JM

Not sure if I've asked this but have you checked your timing. It should be at 28 degrees BTDC with the hoses diconnected and plugged. Then hook the hoses back up and take it for a spin._________________1969 Beetle
1974 Westy FI Conversion

a little off topic but....here is what I did to help my CHT issue in the bus (retro fitted with a 77-78 FI system)

Turns out I had the wrong distributor for the FI system so I traced the model year down for the FI I had and found the right distributor for it. Apparently the old unit was advancing too far when I got on the throttle thus heating up the heads. That's right I said thus. Anyway, this new unit helped a lot with the CHTs. If anyone is still reading, the full story from the samba is below

I found a 022-905-205S distributor in the classified and had it rebuilt by the philbin group. They did a great job and a pretty fast turn around. The distributor came back looking like a new unit with all the bits replaced or renewed. I almost didn't want to install it, it looked so nice

Installed it in the bus, timed it to 28 degrees with the vacuum tube unplugged, then took it for a spin, (after plugging in the vacuum line). I had a little bit less power but the CHTs were MUCH lower. Hovering around 350-360 rather then the 390-400 range I was seeing. I may add a few more degrees of timing after the distributor gets "settled" but so far I'm pleased._________________1969 Beetle
1974 Westy FI Conversion